Honey bee colonies might not only suffer from collapse
when mortality rates of brood and adult bees increase due
to virus infection but also when virus infections negative-
ly affect bee behavior and, thus, colony performance.

This aspect has been studied in adult forager bees
injected with as little as 44 copies of IAPV and equipped
with radio frequency identification (RFID) tags. While no
mortality was observed, homing ability was significantly
reduced at 2 and 3 days post-infection. Indeed, only
between 2.3% and 0% of IAPV infected foragers found
their way back, compared to 50% of those injected with
PBS [79]. 

It is reasonable to suspect that a considerable
proportion of foragers not returning to the hive may have
detrimental effects on the colony and contribute to weak-
ening and eventually collapse of the entire colony.

It is widely accepted by now that
Varroa serves as a biological vector of DWV, and thereby
plays a crucial role in the virulence of DWV. The selection
of an especially virulent variant of DWV through
Varroa has been anticipated and discussed for some time.

McMenamin, A. J., & Genersch, E. (2015). Honey bee colony losses and associated viruses. Current Opinion in Insect Science.
             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html